clean up use of _WIN32

Replace the use of _WIN32 in libc++. Replace most use with a C runtime
check _LIBCPP_MSVCRT or the new _LIBCPP_WIN32 to indicate that we are
using the Win32 API. Use a new _LIBCPP_WCHAR_IS_UCS2 to indicate that we
are on an environment that has a short wchar_t.

llvm-svn: 290910

1 files changed, 6 insertions, 8 deletions

diff --git a/libcxx/include/support/win32/support.h b/libcxx/include/support/win32/support.h
index 6a5763b5e49..10572191341 100644
--- a/libcxx/include/support/win32/support.h
+++ b/libcxx/include/support/win32/support.h
@@ -110,10 +110,11 @@ _LIBCPP_ALWAYS_INLINE int __builtin_ctzll(unsigned long long mask)
   unsigned long where;
 // Search from LSB to MSB for first set bit.
 // Returns zero if no set bit is found.
-#if defined(_WIN64)
+#if (defined(_M_ARM) || defined(__arm__)) ||                                   \
+    (defined(_M_AMD64) || defined(__x86_64__))
   if (_BitScanForward64(&where, mask))
     return static_cast<int>(where);
-#elif defined(_WIN32)
+#else
   // Win32 doesn't have _BitScanForward64 so emulate it with two 32 bit calls.
   // Scan the Low Word.
   if (_BitScanForward(&where, static_cast<unsigned long>(mask)))
@@ -121,8 +122,6 @@ _LIBCPP_ALWAYS_INLINE int __builtin_ctzll(unsigned long long mask)
   // Scan the High Word.
   if (_BitScanForward(&where, static_cast<unsigned long>(mask >> 32)))
     return static_cast<int>(where + 32); // Create a bit offset from the LSB.
-#else
-#error "Implementation of __builtin_ctzll required"
 #endif
   return 64;
 }
@@ -152,10 +151,11 @@ _LIBCPP_ALWAYS_INLINE int __builtin_clzll(unsigned long long mask)
   unsigned long where;
 // BitScanReverse scans from MSB to LSB for first set bit.
 // Returns 0 if no set bit is found.
-#if defined(_WIN64)
+#if (defined(_M_ARM) || defined(__arm__)) ||                                   \
+    (defined(_M_AMD64) || defined(__x86_64__))
   if (_BitScanReverse64(&where, mask))
     return static_cast<int>(63 - where);
-#elif defined(_WIN32)
+#else
   // Scan the high 32 bits.
   if (_BitScanReverse(&where, static_cast<unsigned long>(mask >> 32)))
     return static_cast<int>(63 -
@@ -163,8 +163,6 @@ _LIBCPP_ALWAYS_INLINE int __builtin_clzll(unsigned long long mask)
   // Scan the low 32 bits.
   if (_BitScanReverse(&where, static_cast<unsigned long>(mask)))
     return static_cast<int>(63 - where);
-#else
-#error "Implementation of __builtin_clzll required"
 #endif
   return 64; // Undefined Behavior.
 }